How do you assess that, you ask? Of course you can't do that on one week, month or even season's results, nor one major trophy. Nottingham Forest won the European Cup in 1979 and 1980, but their Chairman and Manager have both just resigned and they languish in The Championship.

So obviously whatever measures you use have to be over a period of time. Consistency is the key.

Among the inevitable contenders are Barcelona, Real Madrid, Bayern Munich, Liverpool and Chelsea. The two Milan sides have slipped and the South American sides don't really come into contention, mainly because there isn't the same amount of money in their competitions.

So what we need is a composite measure. While no club will come out atop all categories, we contend that Manchester United is the best overall.

Please add other contenders and other reasons why, but for the time being, here are the reasons United are the best.

World Club Rankings

This week, Manchester United are top of the World Club Rankings, where they have been all season.

While they drew against FC Basle and Stoke last week, their win against Norwich confirms them as still top.

They have won their last 19 Premier League games at home; they have won six and drawn one of their matches; scored 24 and conceded five; and remain one of a handful of British teams that are unbeaten this season.

Not only do they sit above Manchester City, but they also beat them in the Charity Shield. They have also beaten Arsenal, Chelsea and Tottenham in probably their toughest league start for a very long time.

The Oldest Top Club in the World

One day there will be a statue of Sir Alex Ferguson outside the ground. Between them, he and Sir Matt Busby have managed the club for half a century of its 133-year history.

Manchester United was originally Newton Heath LYR Football Club, founded in 1878, who played in Green and Gold.

They joined their first competitive league in 1888 and were founding members of the Football Alliance, which merged with the Football League. Newton Heath were among the original members of the First Division in 1892/3.

Saved from dissolution by one of its players, Captain Harry Stafford, the club was reborn as Manchester United in April 1902. The rest...as they say...is history.

The Greatest Tradition in the EPL

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Sir Matt Busby wasn't the start of Manchester United's tradition but he had a massive effect on a number of aspects of the club which have never changed.

In particular, he established what is now the United Academy and put his personal stamp on how football is played by the Reds to this day: attack is the best form of defence. He would be proud of the open play by the young team.

It is fair to claim that United have the second best tradition in the world in modern football. While the devastating Munich disaster undoubtedly led to them being adopted as most people's second favourite team after their own, the popularity could not have survived without the eye-catching style of football.

Real Madrid arguably have the strongest traditions in the minds of living supporters who can remember football since the pre-war period. They first brought "the beautiful game" to the attention of the writer in the European Cup Final of 1956.

FC Barcelona are a much more recent phenomenon, even though the current team are arguably one of the best teams ever in world history. But how can they be compared with "the Busby Babes" or the Real Madrid side created by Santiago Bernabeu Yeste, which won the European Cup five consecutive times from 1956 to 1960 with players like Di Stefano, Gento, Kopa and Puskas?

Barcelona only won the Spanish league title once before the War and didn't win the European Cup until 1992, unlike Real Madrid in 1956 and United in 1968.

The Best Managed Club in the World

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Many people regard Sir Alex Ferguson as the greatest manager that ever lived.

It is hard to compare one generation with another. In due course, Pepe Guardiola may come to be regarded in the same vein. Jose Mourinho has already won the Champions League with two different clubs and managed four of the top clubs in Europe.

What we are talking about here, however, is the overall management of the club and especially over a period of time.

While many foreign clubs have a head coach who answers to a Board of Directors, Sir Alex manages the football side and David Gill the business side. They are given free reign by the owners—the Glazers.

This style of management has been largely prevalent since Sir Matt Busby joined the club in 1945. The 66 years since have been dominated by the two Knights for 50 of those years.

But that's not the whole story on continuity. In the 119 years since Manchester United was established in the English First Division, they have had only seventeen different managers.

We shall talk later about the commercial success of United, but for comparison on the football side, Real Madrid have had 49 managers in the last 100 years and 20 since Sir Alex was appointed at Manchester United.

Similarly, while Barcelona have had only nine in the same period, they have had 55 in the last 94 years.

The management and coaching of the club is closely connected with the traditions and the success over the last 66 years has been built on continuity.

Youth Development

It is a moot point whether Manchester United or Barcelona have better player development.

In the EPL, United have no equals and in Europe probably no better over the last 66 years.

Seven of the team who started against Manchester United in the ECL Final were produced from Barcelona's La Masia system. However, this does not mean that they haven't spent heavily to augment this production line.

Pique cost £6 million to buy back from United; Fabregas £35m from Arsenal; Villa £34m; and Sanchez £23m. They have hardly eased either the debt (58 percent of Forbes estimated club worth), nor the salary bill, where the cost per player is estimated to be second only to Real Madrid.

Real Madrid is now renowned for its "Galacticos"—players of world class status, signed at great cost. The most famous include Cristiano Ronaldo (signed at £80m) and Zidane.

Madrid in fact have a much longer tradition of producing their own players and the 1966 European Cup was won with a team entirely composed of Spanish players. La Masia at Barcelona was only born in 1979 as the creation of Johan Cruyff.

However, it could be argued that Sir Matt Busby was the father of youth development with a tradition now captured by the Manchester United Academy. Although some of the Busby Babes—like Tommy Taylor—were bought in, several were homegrown.

United have won the FIFA Youth Cup 17 times and the FA Youth Cup 10 times, including the first five ever played, from 1953 to 1957 and 2011.

All five of the club's top all-time appearance makers were products of the youth system that Sir Matt established in 1945, as were "Fergie's Fledglings."

The production line continues, including Giggs, Welbeck, Cleverley, Evans, Fletcher, Macheda, Gibson, Amos, Pogba and Morrison in the present first team squad.

Also waiting in the wings with a bright future are: Will Keane, Reece Brown, Scott Wootton, Robbie Brady, Ryan Tunnicliffe, Ezekiel Fryers (who played against Leeds), John Cofie, Larnell Cole, Jesse Lingard and a whole host of other young talent, including a total of 30 who have been capped at international level.

Most Loyal Players

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Manchester United have a tradition of player loyalty. It's arguable whether this is better than Barcelona, but it is certainly the best in the Premier League.

When Gary Neville and Paul Scholes retired last year, they had spent their entire playing careers at Old Trafford. United have had a host of one-club players over the years, of which the most famous is probably Sir Bobby Charlton.

Ryan Giggs has just started his 21st season with United at the age of 37. In their entire history, they have had 65 players who have stayed for 10 years or more.

46 of those who have played in the first team for Sir Alex Ferguson have served at least five years at the club.

This is no accident. The majority of players who come to Old Trafford have always wanted to play for the club. Most of the others can't believe their luck. Like Wayne Rooney, when they consider leaving, they wonder if it could be any better at any other club in the world.

Most Watched on TV

On 23 February 2011, a turgid draw between Manchester United and Marseille was watched by 5.623m viewers, taking almost a quarter of the total UK TV audience.

The UEFA Champions League Final between Manchester United and Barcelona was watched by 4.2 million in the US alone. Worldwide, it is estimated to have drawn over 300 million viewers.

Almost 2.5 million in the US watched the United vs Chelsea match last month.

Apart from the Champions League Final, nothing can match Real Madrid vs Barcelona for a one-off TV audience worldwide.

But United's matches can be watched in 1.15 billion homes worldwide, with 190 million receiving MUTV. The weekly audience is as big as that of a Superbowl. David Gill claims that at any one time, there are between 80 and 100 thousand MUTV subscriptions in the UK alone.

Since the Premier League began, Manchester United have been the highest earners from the Sky contract and the most watched team in the Premier League.

Depending on which measure you use, Barcelona or Real Madrid may be more watched for the games between themselves, but United are definitely the most watched in the EPL for the last 20 years.